Answer: During the Cambrian Explosion of Animal Life
 
        
             
        
        
        
I think the correct term to fill in the blanks would be glycerol phosphate electron shuttle. This shuttle is responsible of transporting agents that are reducing into the inner membrane of the mitochondria. Since NADH cannot enter, it is reduced so that the electrons could go in to the transport chain.
        
             
        
        
        
Fire can be accidental or intentional, and it can cause erosion.
        
                    
             
        
        
        
Answer:
3 ways to understand the differences between compounds and mixtures are described below in explanation.
Explanation:
1. In a mixture, no new product is formed. It is a simple tacking of two molecules without any chemical reaction occurring. For example water and sand. Compound is a new substance formed by chemical reactions occurring between various molecules. For example, carbon and oxygen combine to form carbon dioxide.
2. A compound is always homogeneous whereas a mixture can be homogeneous or heterogeneous.
3. Compounds have a fixed boiling and melting temperature. Whereas, mixtures do not have a definite melting and boiling temperature.